As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON THE GROUND SMOKE SMELL NOTED IN THE CABIN. VISUALLY IDENTIFIED AS BLUE SMOKE. DETERMINED THE OIL SMOKE/SMELL TO BE FROM THE AUXILIARY POWER UNIT. COMPLIED WITH MAINTENANCE TASK CARD 8301001, TO PURGE SMOKE FROM CABIN. NO MORE SMOKE OR SMELL NOTED. PLACED AUXILIARY POWER UNIT ON MEL, REFERENCE 49-1. MEL CLEARED ON 6/4/97 BY REPLACING THE APU, OPERATIONAL CHECKS GOOD.